Synthetic method and application of daphnetin derivatives
阅读说明：本技术 一类瑞香素衍生物的合成方法和应用 (Synthetic method and application of daphnetin derivatives ) 是由 蒋建勤 吕俊霖 陶冶 于 2021-07-19 设计创作，主要内容包括：本发明属于医药技术领域。本发明公开了一种瑞香素衍生物及其制备方法和医药用途,涉及结构通式(I)所示的7-OH、8-OH位取代的瑞香素衍生物,该衍生物通过瑞香素与N-Boc溴乙胺发生醚化反应得到中间体II,中间体II再与三氟乙酸反应脱去Boc基团得到中间体III,中间体III再与能够改善化合物的生物利用度的取代基团发生酰胺缩合反应制备得到。经活性筛选试验证明,本发明的化合物具备α-葡萄糖苷酶抑制作用,且活性优于原料瑞香素,具有治疗II型糖尿病的相关医用用途,且本发明提供的瑞香素衍生物的制备方法步骤简单,条件温和,可操作性和可控性较强。现有技术没有公开过本发明衍生物及其制备方法和医药用途。(The invention belongs to the technical field of medicines. The invention discloses a daphnetin derivative and a preparation method and medical application thereof, and relates to a 7-OH and 8-OH substituted daphnetin derivative shown in a structural general formula (I), wherein the derivative is prepared by carrying out etherification reaction on daphnetin and N-Boc bromoethylamine to obtain an intermediate II, reacting the intermediate II with trifluoroacetic acid to remove a Boc group to obtain an intermediate III, and carrying out amide condensation reaction on the intermediate III and a substituent group capable of improving the bioavailability of a compound. The activity screening test proves that the compound has the alpha-glucosidase inhibition effect, the activity of the compound is superior to that of daphnetin serving as a raw material, the compound has related medical application for treating type II diabetes, and the preparation method of the daphnetin derivative provided by the invention has the advantages of simple steps, mild conditions, and strong operability and controllability. The prior art does not disclose the derivative, the preparation method and the medical application thereof.)
1. A daphnetin 7-OH, 8-OH derivative has the following structural formula:
in the general structural formula (I), the substituent R is selected from the following substituent group compounds capable of improving the bioavailability of the compound: benzoyl chloride, propionyl chloride, thiophenecarbonyl chloride, butyryl chloride, cyclopropyl formyl chloride, furoyl chloride, acetyl chloride, ibuprofen, ligustrazine and pyridine.
Wherein: compound 1: r1＝R2A benzoyl group; compound 2: r1＝R2Propionyl group;
compound 3: r1＝R2A thienyl group; compound 4: r1＝R2Butyryl;
compound 5: r1＝R2(ii) cyclopropylformyl; compound 6: r1＝R2Furan formyl;
compound 7: r1＝R2Acetyl group;
compound 8: r1＝H、R22- (4-isobutylbenzene) propanoyl;
compound 9: r1＝H、R22, 3, 5-trimethylpyrazinoyl;
compound 10: r1＝H、R22-picolinoyl.
2. A process for the preparation of daphnetin 7-OH, 8-OH derivatives as claimed in claim 1, comprising the steps of:
step a, performing etherification reaction on daphnetin and N-Boc bromoethylamine to obtain an intermediate II shown in the following structural formula;
step b, reacting the intermediate II with trifluoroacetic acid to remove Boc group, and exposing amino to obtain an intermediate III shown in the following structural formula;
c, carrying out amide condensation reaction on the intermediate III and the connecting group to prepare a compound 1-compound 7;
and d, carrying out amide condensation reaction on the intermediate III and the connecting group to prepare a compound 8-compound 10.
3. The method according to claim 2, wherein the etherification reaction conditions in step a include: potassium iodide is used as a catalyst, potassium carbonate is used as a base, and the reaction temperature is 80 ℃.
4. The method of claim 3, wherein step a comprises: daphnetin, potassium carbonate and potassium iodide were first dissolved in anhydrous DMF and stirred magnetically. Heating at 80 deg.C for 40min, slowly adding N-Boc bromoethylamine dropwise, reflux reacting at 80 deg.C, adding N at the top of reflux device2And a protection device. Monitoring the reaction progress by TLC; after the reaction is finished, adding a proper amount of diluted hydrochloric acid, stirring and neutralizing until the mixture is acidic, extracting for three times by using ethyl acetate, and collecting an ethyl acetate layer; and washing the ethyl acetate layer with distilled water and saturated salt solution for three times respectively, drying with anhydrous sodium sulfate, performing suction filtration, performing reduced pressure spin-drying on the filtrate, and separating and purifying the residue by column chromatography to obtain an intermediate II.
5. The process of claim 2, wherein the reaction conditions in step b comprise reaction with trifluoroacetic acid (CF)3COOH) is a reagent for removing Boc groups, and the reaction is carried out at normal temperature.
6. The method of claim 5, wherein step b comprises: placing the intermediate II in a single-neck flask, and adding dichloromethane (CH)2Cl2) After dissolution, excess CF is added3COOH, stirring and reacting for 2h at room temperature, and monitoring the reaction process by a TLC plate; after the reaction was complete, saturated NaHCO was slowly added3Adjusting the solution to alkaline, extracting with n-butanol, and collecting n-butanol layer; washing n-butanol layer with distilled water and saturated saline solution for three times, collecting n-butanol layer, drying with anhydrous sodium sulfate, vacuum filtering, and spin-drying the filtrate under reduced pressureAnd separating and purifying the residue by column chromatography to obtain an intermediate III.
7. The process according to claim 2, wherein the amide condensation reaction conditions in step c comprise triethylamine (Et)3N) is used as alkali, and the reaction is carried out at normal temperature.
8. The method of claim 7, wherein step c comprises: dissolving intermediate III in CH2Cl2Put into a single-neck flask, added with Et3N, slowly adding acyl chloride with different substituents, reacting the mixture at room temperature for 8 hours, and monitoring the reaction process by using a TLC plate; after the reaction is completed, collecting CH2Cl2A layer; CH (CH)2Cl2The layers were washed with distilled water and saturated brine three times each, and CH was collected2Cl2Drying the layer with anhydrous sodium sulfate, suction filtering, spin-drying the filtrate under reduced pressure, and separating and purifying the residue with silica gel column chromatography to obtain the target compound 1-compound 7.
9. The method according to claim 2, wherein the amide condensation reaction conditions in step d comprise a reaction at room temperature using 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDCI), 1-hydroxybenzotriazole (HOBt) as a condensing agent, and N, N-Diisopropylethylamine (DIPEA) as a base.
10. The method of claim 9, wherein step d comprises: adding EDCI, HOBt, DIPEA and substituted carboxylic acid into a single-neck round-bottom flask, dissolving the compound with N, N-Dimethylformamide (DMF), placing the mixture at room temperature, stirring and reacting for 1h, dissolving an intermediate III into DMF, adding the mixture into a reaction system, adding water to quench and dilute after monitoring the reaction by a TLC plate, extracting for 3 times by ethyl acetate, combining ethyl acetate layers, washing by distilled water and saturated saline water for three times respectively, drying by anhydrous sodium sulfate, carrying out suction filtration, carrying out reduced pressure spin drying on filtrate, and separating and purifying the residue by silica gel column chromatography to obtain the target compound 8-compound 10.
11. Daphnetin 7-OH, 8-OH derivative according to claim 1, has the effect of inhibiting alpha-glucosidase and related medical uses for the treatment of type II diabetes.
Technical Field
The invention belongs to the field of natural medicinal chemistry, relates to a novel natural compound derivative, and particularly relates to a daphnetin derivative, and a preparation method and medical application thereof.
Background
Diabetes is a common clinical disease worldwide, and seriously threatens human health. Having become a major challenge for the public health system, while many scientists have been working on developing new treatments for treating diabetes, it remains a clinical hotspot and difficulty of global concern. Diabetes mellitus is a lifelong metabolic disease characterized by chronic hyperglycemia caused by various diseases, and is classified into type I diabetes mellitus and type II diabetes mellitus, both of which have genetic characteristics. Studies have shown that postprandial high blood glucose levels are a major factor in the development and progression of type II diabetes. In recent years, a large number of drugs for treating type II diabetes have been developed, most of which are natural products or derivatives thereof.
Daphnetin, also known as daphnetin A, is an effective component extracted from daphne giraldii nitsche, mainly exists in daphne plants, and has pharmacological effects of diminishing inflammation, relieving pain, and inhibiting alpha-glucosaccharase. However, daphnetin has the limitations of poor water solubility, low bioavailability, poor stability and the like, so that the application of daphnetin in medicines is limited. Therefore, the invention determines to use the effective components in natural plants as leads to carry out structural modification, and carries out structural modification on daphnetin so as to expect to obtain the compound with better stability and higher bioavailability.
The daphnetin is structurally modified to obtain a series of derivatives. The purpose is basically achieved through preliminary pharmacological experiments, and the preparation method is expected to provide related medical application for treating the type II diabetes and has good application prospect.
Disclosure of Invention
One of the purposes of the invention is to provide a daphnetin derivative.
The invention also aims to provide a preparation method of the daphnetin derivative.
Still another object of the present invention is to provide a medical use of the aforementioned daphnetin derivative.
In order to realize the purpose, the invention provides 7-OH and 8-OH substituted daphnetin derivatives shown in a structural general formula (I), and through screening of alpha-glucosaccharase inhibition activity, most compounds have good in vitro activity and can be used as precursor compounds for further developing alpha-glucosaccharase inhibitors.
The 7-OH and 8-OH substituted daphnetin derivative provided by the invention is represented by a structural general formula (I):
in the general structural formula (I), the substituent R is selected from the following substituent group compounds capable of improving the bioavailability of the compound: benzoyl chloride, propionyl chloride, thiophenecarbonyl chloride, butyryl chloride, cyclopropylcarbonyl chloride, furoyl chloride, acetyl chloride, ibuprofen, ligustrazine, pyridine;
wherein: compound 1: r1＝R2A benzoyl group; compound 2: r1＝R2Propionyl group;
compound 3: r1＝R2A thienyl group; compound 4: r1＝R2Butyryl;
compound 5: r1＝R2(ii) cyclopropylformyl; compound 6: r1＝R2Furan formyl;
compound 7: r1＝R2Acetyl group;
compound 8: r1＝H、R22- (4-isobutylbenzene) propanoyl;
compound 9: r1＝H、R22, 3, 5-trimethylpyrazinoyl;
compound 10: r1＝H、R22-pyridineformyl;
the preparation method of the 7-OH and 8-OH substituted daphnetin derivative comprises the following steps: etherification reaction and amide condensation reaction.
The invention also provides a preparation method of the daphnetin 7-OH and 8-OH derivatives, which comprises the following operation steps:
step a, performing etherification reaction on daphnetin and N-Boc bromoethylamine to obtain an intermediate II shown in the following structural formula;
step b, reacting the intermediate II with trifluoroacetic acid to remove Boc group, and exposing amino to obtain an intermediate III shown in the following structural formula;
c, carrying out amide condensation reaction on the intermediate III and the connecting group to prepare a compound 1-compound 7;
d, carrying out amide condensation reaction on the intermediate III and the connecting group to prepare a compound 8-compound 10;
preferably, the etherification reaction conditions in step a include: potassium iodide (KI) is used as a catalyst, and potassium carbonate (K) is used2CO3) As the alkali, the reaction temperature is 80 ℃.
More preferably, step a comprises: firstly daphnetin (1eq), K2CO3(3eq) and KI (0.1eq) were dissolved in anhydrous DMF and stirred magnetically. Heating at 80 deg.C for 40min, slowly adding N-Boc bromoethylamine (3eq) dropwise, refluxing at 80 deg.C for reaction, and adding N at the top of the refluxing device2And a protection device. Monitoring the reaction process by TLC; after the reaction is finished, adding a proper amount of diluted hydrochloric acid, stirring and neutralizing until the mixture is acidic, extracting for three times by using ethyl acetate, and collecting an ethyl acetate layer; and washing the ethyl acetate layer with distilled water and saturated salt solution for three times respectively, drying with anhydrous sodium sulfate, performing suction filtration, performing reduced pressure spin-drying on the filtrate, and separating and purifying the residue by silica gel column chromatography to obtain an intermediate II.
Preferably, the Boc removal reaction conditions in step b include: with trifluoroacetic acid (CF)3COOH) is a reagent for removing Boc groups, and the reaction is carried out at normal temperature.
More preferably, step b comprises: placing the intermediate II (1eq) in a single-neck flask, using CH2Cl2After dissolution, excess CF is added3COOH (30eq), left at room temperature and stirred for 2h, and the progress of the reaction is monitored by TLC plate; after the reaction was complete, saturated NaHCO was slowly added3Adjusting the solution to alkaline, extracting with n-butanol, and collecting n-butanol layer; washing the n-butanol layer with distilled water and saturated brine for three times, collecting the n-butanol layer, drying with anhydrous sodium sulfate, vacuum filtering, spin-drying the filtrate under reduced pressure, and separating and purifying the residue with silica gel column chromatography to obtain intermediate III.
Preferably, the amide condensation reaction conditions in step c comprise: with triethylamine (Et)3N) is alkali, and the reaction is carried out at normal temperature.
More preferably, step c comprises: intermediate III (1eq) was dissolved in dichloromethane (CH)2Cl2) Put into a single-neck flask, added with Et3N (3eq), the acyl chloride (1.5eq) of different substituents was added slowly and the mixture was allowed to react at room temperature for 8h, monitoring the progress of the reaction with TLC plates; after the reaction is completed, collecting CH2Cl2A layer; CH (CH)2Cl2The layers were washed with distilled water and saturated brine three times each, and CH was collected2Cl2Drying the layer with anhydrous sodium sulfate, suction filtering, spin-drying the filtrate under reduced pressure, and separating and purifying the residue with silica gel column chromatography to obtain the target compound 1-compound 7.
Preferably, the amide condensation reaction conditions in step d include: 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDCI) and 1-hydroxybenzotriazole (HOBt) are used as condensing agents, N, N-Diisopropylethylamine (DIPEA) is used as alkali, and the reaction is carried out at normal temperature.
More preferably, step d comprises: adding EDCI (1.5eq), HOBt (1.5eq) and DIPEA (2.5eq) into a single-neck round-bottom flask (50mL), replacing carboxylic acid (1eq), dissolving the compound with N, N-Dimethylformamide (DMF), reacting at room temperature for 1h, dissolving the intermediate III (1eq) in DMF, adding the mixture into the reaction system, monitoring by a TLC plate, adding water to quench and dilute the mixture, extracting the mixture with ethyl acetate for 3 times, combining ethyl acetate layers, washing the mixture with distilled water and saturated saline water for three times respectively, drying the mixture with anhydrous sodium sulfate, performing suction filtration, performing rotary drying on the filtrate under reduced pressure, and performing chromatographic separation and purification on the residue by a silica gel column to obtain the target compound 8-10.
The daphnetin derivative substituted at the 7-OH and 8-OH positions prepared by the invention is developed into an alpha-glucosidase inhibitor and is used for preventing and treating diseases such as chronic hyperglycemia and the like, and the activity of the compound for treating type II diabetes is evaluated by taking screening of the alpha-glucosidase inhibitory activity as a carrier.
Screening for α -glucosidase inhibitory activity of compounds α -glucosidase (purchased from sigma aldrich trade ltd) was used.
The daphnetin derivative substituted at the 7-OH and 8-OH positions prepared by the invention still shows more obvious inhibitory activity under the concentration of 20 mu mol/L by screening the activity of alpha-glucosidase.
According to the present invention, other various modifications, substitutions and alterations can be made without departing from the technical spirit of the present invention in accordance with the common technical knowledge and conventional means in the field.
The following examples are provided to further complement the above description, but it should not be construed that the scope of the present invention is limited to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention.
Detailed Description
The invention is better illustrated by the following examples. However, the present invention is not limited to the following examples.
The process flow is as follows, and the room temperature or the rt in the preparation method are both referred to as the normal temperature:
example 1
Synthesis of Compound 1
(1) Synthesis of intermediate II
Daphnetin (178mg, 1mmol) and anhydrous potassium carbonate (K) were weighed2CO3414mg, 3mmol), potassium iodide (KI, 16.6mg, 0.1mmol) was added to a round bottom flask, 100mL of N, N-Dimethylformamide (DMF) was used as a solvent, and N was added to the top of the reflux apparatus2Protection device, magnetic stirring. After heating at 80 ℃ for 40min, N-Boc bromoethylamine (508.7. mu.L, 3mmol) was slowly added dropwise, the reaction was refluxed for 72h, and the reaction was terminated after TLC plate monitoring. The reaction mixture is slowly cooled at room temperature, 20mL of distilled water is added for dilution, 3mol/L of dilute hydrochloric acid is added for adjusting the pH value to acidity, ethyl acetate is used for extraction, an ethyl acetate layer is collected and washed by distilled water and saturated saline solution for three times respectively,collecting the organic layer, drying with anhydrous sodium sulfate, and recovering the solvent by suction filtration to obtain a crude product. Silica gel column chromatography with petroleum ether/ethyl acetate 3: 1 (V: V) as eluent gave a yellow solid (134.4mg, 0.4mmol), yield: 40 percent.
(2) Synthesis of intermediate III
Intermediate II (134.4mg, 0.4mmol) was taken out and placed in a single-necked flask (50mL), and after dichloromethane (6mL) was added and dissolved, excess trifluoroacetic acid (CF) was added3COOH, 174. mu.L and 12mmol) and left at room temperature for stirring reaction for 2h, monitoring the reaction progress by TLC plate, and after the reaction is finished, slowly adding saturated NaHCO3The solution was adjusted to make the reaction solution alkaline. Extracting with n-butanol, collecting n-butanol layer, washing with distilled water and saturated saline solution for three times, collecting organic layer, drying with anhydrous sodium sulfate, vacuum filtering, recovering solvent to obtain crude product, and performing silica gel column chromatography with dichloromethane and methanol at ratio of 10: 1 (V: V) as eluent to obtain light yellow solid (66mg, 0.3mmol), yield: 75 percent.
(3) Synthesis of Compound 1
Intermediate III (66mg, 0.3mmol) was dissolved in 10mL CH2Cl2Placing the mixture into a single-neck flask (50mL), adding triethylamine (75 mu L, 0.9mmol), slowly adding benzoyl chloride (0.45mmol), reacting the mixture at room temperature for 8 hours, monitoring the reaction process by using a TLC plate, after the reaction is finished, washing a dichloromethane layer for three times by using distilled water and saturated saline water respectively, collecting the dichloromethane layer, drying the dichloromethane layer by using anhydrous sodium sulfate, and carrying out suction filtration to recover a solvent to obtain a crude product. The crude product was purified by silica gel column chromatography (chloroform: acetone ═ 10: 1, V: V) to give the pure product as a white solid. Total yield: 20.0%, melting point: 140 ℃ and 142 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR(600MHz，CDCl3)：δH 8.14(m，2H)，7.77(dd，J＝8.1，1.4Hz，2H)，7.72(d， J＝9.6Hz，1H)，7.62(td，J＝7.4，1.2Hz，1H)，7.45(t，J＝7.6Hz，3H)，7.38(t，J＝7.6Hz，2H)， 7.29(d，J＝8.4Hz，1H)，7.16(d，J＝8.4Hz，1H)，6.43(d，J＝9.6Hz，1H)，4.42(t，J＝4.9Hz，2H). 13C-NMR(150MHz，CDCl3)：δC167.50，164.48，159.37，147.92，146.39，143.45，138.34，134.29， 133.99，131.39，130.29，128.86，128.45，128.16，127.12，122.70，119.47，118.17，116.12，73.46， 40.11.HR-ESI-MS：m/z 430.1284[M+H]+(calcd for C25H20NO6，430.1284).
Example 2
Synthesis of Compound 2
Referring to example 1, step 3 was carried out using propionyl chloride instead of benzoyl chloride under the same conditions as in example 1 to obtain a pure white solid. Total yield: 21.5%, melting point: 160 ℃ and 162 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR (500MHz，CDCl3)：δH 7.69(d，J＝9.6Hz，1H)，7.23(d，J＝8.5Hz，1H)，7.02(d，J＝8.5Hz，1H)， 6.40(d，J＝9.6Hz，1H)，4.23(t，J＝5.0Hz，2H)，3.63(q，J＝5.2Hz，2H)，2.67(q，J＝7.5Hz，2H)， 2，31(q，J＝7.6Hz，2H)，1.30(t，J＝7.6Hz，3H)，1.18(t，J＝7.6Hz，3H).13C-NMR(125MHz， CDCl3)：δC174.27，172.12，159.32，147.91，146.36，143.44，138.28，122.68，119.35，117.99，116.01， 73.57，39.61，29.64，27.54，9.81，9.09.ESI-MS：m/z 356.1[M+Na]+(calcd for C17H19NNaO6， 356.1).
Example 3
Synthesis of Compound 3
Referring to example 1, step 3 was carried out using thenoyl chloride instead of benzoyl chloride under the same conditions as in example 1 to obtain a pure white solid. Total yield: 20.5%, melting point: 126 ℃ and 130 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR (600MHz，CDCl3)：δH 7.96(dd，J＝3.8，1.2Hz，1H)，7.72(d，J＝9.6Hz，1H)，7.66(dd，J＝5.0，1.2 Hz，1H)，7.57(dd，J＝3.8，1.0Hz，1H)，7.44(dd，J＝5.0，1.1Hz，1H)，7.28(d，J＝8.5Hz，1H)， 7.18(d，J＝8.5Hz，1H)，7.14(dd，J＝5.0，3.8Hz，1H)，7.04(dd，J＝5.0，3.8Hz，1H)，6.43(d，J＝ 9.6Hz，1H)，4.41(t，J＝4.8Hz，2H)，3.76(q，J＝5.2Hz，2H).13C-NMR(150MHz，CDCl3)：δC 162.06，159.74，159.41，147.87，145.92，143.47，138.93，138.27，135.62，134.55，131.15，130.14， 128.41，128.10，127.67，122.67，119.47，118.22，116.16，73.49，40.00.ESI-MS：m/z 464.1[M+ Na]+(calcd for C21H15NNaO6S2，464.1).
Example 4
Synthesis of Compound 4
Referring to example 1, step 3 was carried out under the same conditions as in example 1 except that butyryl chloride was used instead of benzoyl chloride, to obtain a pure white solid. Total yield: 23.5%, melting point: 155 ℃ and 160 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR (500MHz，CDCl3)：δH 7.74(d，J＝9.6Hz，1H)，7.28(d，J＝8.5Hz，1H)，7.07(d，J＝8.4Hz，1H)， 6.45(d，J＝9.5Hz，1H)，4.28(t，J＝4.9Hz，2H)，3.68(q，J＝5.1Hz，2H)，2.66(t，J＝7.4Hz，2H)， 2.31(t，J＝7.5Hz，2H)，1.86(p，J＝7.4Hz，2H)，1.75(p，J＝7.4Hz，2H)，1.12(t，J＝7.4Hz，3H)， 1.00(t，J＝7.4Hz，3H).13C-NMR(125MHz，CDCl3)：δC 173.64，171.40，159.42，148.03，146.45， 143.57，138.43，122.80，119.52，118.10，116.12，73.76，39.71，38.68，36.08，19.29，18.58，13.91， 13.77.HR-ESI-MS：m/z 362.1600[M+H]+(calcd for C19H24NO6，362.1598).
Example 5
Synthesis of Compound 5
Referring to example 1, step 3 was carried out using cyclopropylcarbonyl chloride instead of benzoyl chloride under the same conditions as in example 1 to obtain a pure white solid. Total yield: 27.6%, melting point: 166 ℃ and 170 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR(600MHz，CDCl3)：δH 7.72(d，J＝9.6Hz，1H)，7.25(d，J＝8.5Hz，1H)，7.06(d，J＝8.5 Hz，1H)，6.42(d，J＝9.5Hz，1H)，4.28(t，J＝4.9Hz，2H)，3.68(q，J＝5.2Hz，2H)，1.94(tt，J＝8.3， 4.6Hz，1H)，1.59(tt，J＝7.9，4.6Hz，1H)，1.24(dt，J＝6.9，3.6Hz，2H)，1.13(dq，J＝7.6，4.2Hz， 2H)，0.98(dt，J＝6.6，3.4Hz，2H)，0.76(dq，J＝7.2，3.9Hz，2H).13C-NMR(150MHz，CDCl3)：δC 173.94，172.75，159.43，147.83，146.32，143.53，138.36，122.63，119.40，117.94，115.93，73.70， 39.81，14.61，12.82，9.74，7.25.ESI-MS：m/z 380.1[M+Na]+(calcd for C19H19NNaO6，380.1).
Example 6
Synthesis of Compound 6
Referring to example 1, step 3 was carried out using furoyl chloride instead of benzoyl chloride under the same conditions as in example 1 to obtain a pure white solid. Total yield: 24.1%, melting point: 178 ℃ and 180 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR (600MHz，CDCl3)：δH 7.72(d，J＝9.6Hz，1H)，7.65(d，J＝1.7Hz，1H)，7.42(m，2H)，7.28(t，J＝ 4.3Hz，2H)，7.17(d，J＝8.5Hz，1H)，7.09(d，J＝3.4Hz，1H)，6.56(dd，J＝3.6Hz，1.7Hz，1H)， 6.48(dd，J＝3.5，1.8Hz，1H)，6.44(d，J＝9.6Hz，1H)，4.41(t，J＝5.0Hz，2H)，3.79(q，J＝5.3Hz， 2H).13C-NMR(150MHz，CDCl3)：δC 159.30，158.46，155.86，147.90，147.79，147.70，145.46， 144.08，143.33，142.92，138.41，122.65，120.55，119.26，118.27，116.26，114.11，112.46，111.88， 73.37，39.29.ESI-MS：m/z 432.1[M+Na]+(calcd for C21H15NNaO8，432.1).
Example 7
Synthesis of Compound 7
Referring to example 1, pure white solid was obtained by substituting acetyl chloride for benzoyl chloride in step 3 under the same conditions as in example 1. Total yield: 30.0%, melting point: 140 ℃ and 145 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR (600MHz，CDCl3)：δH 7.69(d，J＝9.6Hz，1H)，7.24(d，J＝8.5Hz，1H)，7.02(d，J＝8.4Hz，1H)， 6.40(d，J＝9.6Hz，1H)，4.23(t，J＝4.9Hz，2H)，3.62(q，J＝5.2Hz，2H)，2.37(s，3H)，2.08(s，3H). 13C-NMR(150MHz，CDCl3)：δC 170.76，168.68，159.44，147.96，146.28，143.59，138.36，122.87， 119.41，118.17，116.15，73.58，39.86，23.35，20.88.ESI-MS：m/z 328.1[M+Na]+(calcd for C15H15NNaO6，328.1).
Example 8
Synthesis of Compound 8
Referring to example 1, step 1 and step 2 were the same, and step 3 was performed by adding EDCI (86mg, 0.45mmol), HOBt (61mg, 0.45mmol), DIPEA (131 μ L, 0.75mmol), ibuprofen (0.45mmol) to a single-neck round-bottom flask (50mL), dissolving the above compound with 6mL DMF, reacting at room temperature for 1h, then dissolving intermediate III (66mg, 0.3mmol) obtained in step 2 in 8mL DMF, adding to the reaction system, monitoring the reaction by TLC plate, adding water to quench and dilute, extracting with ethyl acetate for 3 times, combining ethyl acetate layers, washing with distilled water, washing with saturated brine, drying with anhydrous sodium sulfate, recovering the solvent by suction filtration to obtain a crude product, and purifying the crude product by silica gel column chromatography (petroleum ether: ethyl acetate ═ 1: 1, V: V) to obtain a pure pale yellow solid product. Total yield: 11.4%, melting point: 120-122 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR(600MHz，CDCl3)：δH 7.64(d，J＝9.5Hz，1H)，7.25(d，J＝8.0 Hz，2H)，7.15(d，J＝7.9Hz，2H)，7.11(d，J＝8.5Hz，1H)，6.92(d，J＝8.5Hz，1H)，6.19(d，J＝9.5 Hz，1H)，4.28(m，2H)，3.70(q，J＝7.2Hz，1H)，3.53(m，2H)，2.47(d，J＝7.1Hz，2H)，1.87(dp，J ＝13.6，6.8Hz，1H)，1.59(d，J＝7.2Hz，3H)，0.89(d，J＝6.6Hz，6H).13C-NMR(150MHz， CDCl3)：δC 177.11，160.73，153.84，147.52，144.37，141.05，137.97，133.86，129.81，127.52，123.35， 113.48，112.46，111.90，75.56，46.82，45.01，40.95，30.17，22.41，18.52.ESI-MS：m/z 432.2[M+ Na]+(calcd for C24H27NNaO5，432.2).
Example 9
Synthesis of Compound 9
Referring to example 8, ligustrazine is used to replace ibuprofen in step 3, and the other conditions are the same as example 8, thus obtaining a pure white solid product. Total yield: 15.2%, melting point: 215 ℃ and 220 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR(600 MHz，CDCl3)：δH 7.62(d，J＝9.4Hz，1H)，7.09(d，J＝8.6Hz，1H)，6.90(d，J＝8.6Hz，1H)，6.20 (d，J＝9.4Hz，1H)，4.48(m，2H)，3.79(dt，J＝6.7，4.8Hz，2H)，2.95(s，3H)，2.59(s，3H)，2.55(s， 3H).13C-NMR(150MHz，CDCl3)：δC 167.32，160.77，154.93，153.79，151.91，148.12，147.61， 144.44，138.35，133.98，123.43，113.48，112.66，112.16，75.88，40.81，23.14，22.17，21.51.ESI-MS： m/z 392.1[M+Na]+(calcd for C19H19N3NaO5，392.1).
Example 10
Synthesis of Compound 10
Referring to example 8, pyridine was used instead of ibuprofen in step 3, and the conditions were the same as in example 8, to obtain pure white solid. Total yield: 20.1%, melting point: 146 ℃ and 150 ℃. GF254The thin layer of nm silica gel plate is spread into a point.1H-NMR(500 MHz，CDCl3)：δH 8.71(m，1H)，8.57(m，1H)，8.25(d，J＝7.8Hz，1H)，7.87(td，J＝7.7，1.7Hz，1H)，7.61(d，J＝9.5Hz，1H)，7.46(ddd，J＝7.5，4.8，1.2Hz，1H)，7.08(d，J＝8.5Hz，1H)，6.90(d， J＝8.5Hz，1H)，6.19(d，J＝9.5Hz，1H)，4.48(m，2H)，3.81(dt，J＝6.6，4.7Hz，2H).13C-NMR (125MHz，CDCl3)：δC 166.47，160.76，153.77，149.16，148.24，147.52，144.37，137.61，133.89， 126.69，123.32，122.69，113.48，112.53，111.98，75.69，40.95.ESI-MS：m/z 349.1[M+Na]+(calcd for C17H14N2NaO5，349.1).
Example 11
Determination of daphnetin derivative alpha-glucosidase inhibitory activity
The experimental principle is as follows: starch (polysaccharide) in food is digested into oligosaccharide (or called oligosaccharide) containing a few glucose molecules, disaccharide and trisaccharide by oral saliva and pancreatic amylase, enters small intestine, is decomposed into single glucose under the action of alpha-glucosidase, and is absorbed by small intestine. Under physiological conditions, alpha-glucosidase exists in the upper, middle and lower sections of the small intestine, the upper section can be inhibited after the alpha-glucosidase inhibitor is taken, and the absorption of sugar is only in the middle and lower sections, so that the absorption area is reduced, the absorption time is delayed, the food is beneficial to reducing postprandial hyperglycemia, the fasting blood glucose can be reduced after long-term use, and the improvement of insulin sensitivity is estimated to be related to the improvement of the insulin sensitivity. p-nitrophenol-alpha-D-glucoside (pNPG) can be hydrolyzed by alpha-glucosidase to generate p-nitrophenol which is yellow and has specific absorption at 405nm, so that the alpha-glucosidase inhibition activity can be detected by detecting the generation amount of the p-nitrophenol.
The determination method comprises the following steps: the pNPG method, modified for determining the alpha-glucosidase inhibitory activity of the compounds, is reported in the literature. Placing 10 μ L of 0.1U/mL alpha-glucosidase solution in 96-well plate, adding 5 μ L sample solution and 145 μ L of 0.1M PBS buffer solution, incubating in 37 deg.C constant temperature water bath for 10min, adding 40 μ L of 2M pNPG solution, reacting, incubating at 37 deg.C for 20min, and adding 50 μ L of 0.2M Na2CO3The solution stops the reaction. The enzyme activity was quantified by measuring the absorbance at 405 nm. Acarbose was selected as the positive control for the experiment. The parallel operation 3 times (3 times of wells), the average value, the sample on alpha-glucosidase inhibitory activity expressed as inhibition rate.
Inhibition rate calculation formula: inhibition rate [% 1- (A) ]j-Aj0)/(Ai-Ai0)]×100％
Wherein A isjThe absorbance value of the sample group to be detected; a. the0The absorbance value of the sample blank control group is obtained; wherein A isiAbsorbance values for 100% enzyme activity control; a. thei0Is blank control groupThe absorbance value of (a);
continuously selecting 9 concentrations for compound samples with better inhibition rate to determine the inhibition rate, setting 3 multiple holes on each concentration level of each compound sample, and calculating the IC of the compound samples by adopting GraphPad Prism 5 software50The value is obtained.
Table 1: measurement results of alpha-glucosidase inhibitory Activity
Name (R)
Inhibition ratio (%) of 50. mu. mol/L
IC50(μmol/L)
Example 1
41.42
76.91
Example 2
46.33
80.23
Example 3
36.73
96.82
Example 4
41.42
101.87
Example 5
39.10
105.91
Example 6
39.48
106.86
Example 7
32.58
136.74
Example 8
35.33
111.81
Wherein the positive drug acarbose IC50About 183.99. mu. mol/L.
The determination result shows that part of the compounds disclosed by the invention have better inhibition effect on alpha-glucosidase and the activity is better than that of acarbose.
The above embodiments are only used to describe the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, those skilled in the art will recognize that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the technical solutions of the embodiments of the present invention, and the protection scope of the present invention should not be limited to the above specific embodiments.